Ask HN: Something that you learnt and made you go Wow

Any concepts, videos, articles, books, movies, business that opened up a whole new world for you - something that you didn't know earlier or knew little of but then had this WOW / Ah-ha moment for you.

Time, in relation to computers (and all tech really). A company i worked for wanted systems to have no more than 2ns of time drift between each other, in a network of +10 devices. NTP and the like, can only do so much, and the overhead is compounding. During my research i fell down a rabbit hole... A crystal oscillator, even from the same batch of crystal, will have a very slightly different frequency, which means oscillator A and B from the same batch will eventually drift. To solve that, newer tech steps in, MEMS oscillators. These are microscopic tuning forks that vibrate. These give precision oscillations, *however* movement of a MEMS device (ex picking up a machine and moving it, shaking it, etc), like in the case i was exploring, will also cause time drift because the device movement can cause the fork to ping off one of the sides, causing an early, or late, clock tick. Any movement can cause one or more mis-ticks, and a device constantly in motion will cause lots of drift. Crystals at least arent subject to drift as a result of motion (not entirely true, because at a certain speed you can start to have to deal the laws of physics like the analogy of a photon bouncing between two mirrors as you travel toward C). Theoretically, although i havent seen anything about it, you could cause time drift in a MEMS or Crystal oscillator, by yelling at the oscillator (at a certain frequency). Now, we come back to crystals, and discussing temperature, as these oscillators are supposed to be kept at a certain temperature during operation. Any temperature difference between optimal and actual temperature will cause the oscillator to slow down or speed up, causing time drift. MEMS are not susceptible to this, *however* they can be, if you can cause a temperature difference between the fork and the base, you could make the fork expand and hit more quickly, or shrink, and hit slowly. MEMS are also a wild device because the area between the parts is just large enough to allow helium atoms to get stuck between them, and to top it off, helium can squeeze through almost anything, which includes the IC packaging of the MEMS chip, which was discovered when an iphone was left in the vicinity of an MRI machine that was leaking helium.

And thats the rabbit hole of time in relation to electronics. I honestly was never really curious about the whys of "its impossible to have zero time drift over an extended time between two or more electronic devices", i knew it was physics related, but wasnt really curious as to what about it. I know now, and i sorta wish i didnt because i feel like im having a Pepe Silva moment when i have to explain or remember any of this.

The toaster equivalent to a rice cooker is probably an air fryer.

I helped a friend repair a few HP Cesium beam clocks. Once I understood how they actually work, including the Zeeman lines, I was amazed. I love explaining it to others.

Toasters can't even get bread to not burn on the lowest setting